An attempt to block approval of claims that a formula baby milk can improve an infant's eyesight was rejected today.

A vote by Euro-MPs in Strasbourg failed to muster enough support to prevent authorisation of a company's controversial statement about the health benefits for infants of a fatty acid called DHA.

DHA - "docosahexanenoic acid" - is found in small amounts in breast milk and has been recognised as a factor in the development of infants' retinas.

But the same boast for the synthesised version of DHA used in formula milk is still hotly contested by some experts who fear it could mislead mothers of infants.

The EU's Standing Committee on Food Chain and Animal Health has already authorised the declaration by American formula milk manufacturer Mead Johnson that "DHA has a structural and functional role in the retina, and DHA intake contributes to the visual development of infants up to 12 months of age."

But Labour MEP Glenis Willmott, who lead today's bid to halt approval, said there should be more consistent independent evidence before authorisation was given.

The European Food Safety Authority has also warned that there is so far insufficient evidence to justify positive eyesight claims about formula milk DHA.

However, the European Commission is poised to confirm authorisation now that MEPs have failed to muster a big enough vote against the move.

Ms Willmott said she would be appealing to the Commission nevertheless to delay approval pending further independent tests on the formula milk.

"Many doctors are still unconvinced about the benefits. They argue that if DHA really is proven to have the same benefits in bottled milk as it does in breast milk then it should be included in all products, not simply left to manufacturers to use as a marketing gimmick. We need to have a proper debate about these issues," she said.

"It is therefore crucial parents are not misled when trying to make the best choices for their children."

Ms Willmott explained later that a majority of MEPs had voted to block approval - but not by the necessary margin to achieve their aim.

"Today, a majority of this parliament voted against this health claim. MEPs have concluded that scientific consensus simply doesn't exist," she said.

"Yet now manufacturers will be free to target parents with marketing messages that many medical professionals and health organisations believe should not be allowed.

"Parents of young children are a group of consumers who are particularly vulnerable to marketing messages of this kind. Clearly they want to do all they can to give their kids the best start in life. So we have to be extra careful about ensuring they are not misled."

She added: "Clearly, it is a disappointment not to get the number of votes we needed, but this result still sends a strong message that there is deep unease about health claims of this sort.

"Many health professionals have said to me that if DHA really is beneficial in formula milk then it should be required by law to be in all products on sale, not simply left to companies to be used as a marketing tool."

She went on: "It is particularly worrying that the European Commission has seemed resistant to even consider the very valid concerns that have been raised by health and medical organisations.

"The food industry has been lobbying very hard on this claim, not just in the European Parliament over the last few weeks, but targeting the European Commission and scientific establishment for years.

"Health claims are not allowed on normal infant formula milk out of concern that they could be misleading for parents. Many people don't even understand the difference between infant formula and follow-on formula.

"I will be writing to the European Commission to ask for a review of whether health claims on follow-on formula should be allowed."